What is the vaginal microbiome?

By Gabrielle Gleeson-Solomon, CEO of Tota
Scientific Review by Dr Nick Parkinson, PhD
Ask Tota: What is the vaginal microbiome?

You may have heard plenty about the gut microbiome. But your vagina has its own microbiome too and it can play an important part in your vaginal, urinary and reproductive health.
Understanding it may help make sense of changes across your lifetime, from recurrent UTIs and bacterial vaginosis to fertility treatment and menopause.

What is the vaginal microbiome?

The vaginal microbiome is the community of microorganisms, mainly bacteria, that live naturally inside the vagina.
These microorganisms are not automatically harmful. Many are a normal and potentially helpful part of the vaginal environment.
In many women of reproductive age, the vaginal microbiome contains high levels of bacteria from the Lactobacillus group. These bacteria produce lactic acid which helps maintain the vagina’s naturally acidic environment. This can make it harder for some potentially harmful microorganisms to become established.
However, every vaginal microbiome is different. Its composition can vary between women and change within the same person over time. There is no single microbial profile that can be described as perfect for everyone.

The short answer

The vaginal microbiome is:

• A community of bacteria and other microorganisms living in the vagina
• Usually, but not always, rich in Lactobacillus species before menopause
• Influenced by hormones, age, lifestyle, diet, medication and other factors
  
• Connected to vaginal, urinary and reproductive health
  
• Dynamic, meaning it can change throughout your life
  

What does a healthy vaginal microbiome look like?

A healthy vaginal microbiome is one that supports a stable vaginal environment without causing symptoms, but its exact composition varies from person to person.

For many women before menopause, this means a microbiome dominated by one or more Lactobacillus species.

This matters because different does not automatically mean unhealthy. Scientists look at several factors when assessing a vaginal microbiome, including:

• Which microorganisms are present
• Their abundance relative to one another
• Whether potentially protective bacteria are present
• Whether there is an increase in bacteria associated with conditions such as bacterial vaginosis

A microbiome result should be interpreted as part of a wider health picture, not as a diagnosis on its own.

What can change the vaginal microbiome?

The vaginal microbiome is not fixed. It can change in response to diet, lifestyle, hormones, medication, sexual activity and different stages of life.

Factors that may affect its composition include:

• Diet
• Lifestyle (e.g. smoking or excessive drinking)
• The menstrual cycle
• Pregnancy
• Perimenopause and menopause
• Antibiotic use
• Hormonal contraception
• Sexual activity
• Vaginal products and douching
• Infections and some health conditions

Some changes are temporary and settle naturally. Others may be associated with symptoms or a recurrent pattern that deserves further investigation.

That is why one result should never be viewed in isolation. What is happening in your body, how you feel and whether symptoms keep returning all matter.

How is the vaginal microbiome connected to bacterial vaginosis?

Bacterial vaginosis, or BV, is associated with a change in the balance of vaginal bacteria, often involving fewer lactobacilli and an increase in several other types of bacteria, such as gardnerella.
BV may cause a thin, greyish-white discharge and a strong or fishy smell, although around half of women with BV have no symptoms. BV is not simply the presence of one bad bacterium. It usually involves a broader shift in the vaginal environment. This is one reason researchers increasingly study the microbiome rather than looking at individual organisms alone.

However, microbiome testing should not be used to self-diagnose BV. If you have unusual discharge, odour, irritation, pelvic pain or other new symptoms, speak to your healthcare professional. 

Can the vaginal microbiome affect recurrent UTIs?

The vaginal microbiome may influence susceptibility to urinary tract infections, but it is only one part of a complex picture.
The vagina, urethra and bladder are close neighbours. Their microbial communities can overlap and bacteria associated with UTIs may first colonise the area around the vagina before entering the urinary tract.
Research has linked lower levels of some vaginal Lactobacillus species with an increased risk of UTIs, particularly after menopause. Scientists are also studying how the vaginal and urinary microbiomes interact and why some women experience repeated infections while others do not.
This does not mean that an altered vaginal microbiome is always the cause of a UTI. Recurrent urinary symptoms can have several possible explanations and similar symptoms do not always have the same cause.
But if infections or symptoms keep returning, understanding both the vaginal and urinary microbiomes may provide an additional piece of information, especially when routine testing has not explained the pattern.

Can a vaginal microbiome test diagnose a UTI?

No. A vaginal microbiome test cannot diagnose an acute UTI and is not a replacement for clinical assessment.
If you currently have UTI symptoms, seek advice from a healthcare professional. 

What does the vaginal microbiome have to do with fertility?

The vaginal microbiome is relevant to reproductive health, but it cannot tell you whether you will become pregnant or whether fertility treatment will succeed.
Some studies have found associations between vaginal microbiomes with lower levels of Lactobacillus, or greater bacterial diversity, and poorer reproductive or assisted conception outcomes.
However, an association does not prove that the microbiome caused the outcome. Fertility depends on many interconnected factors, including ovulation, egg and sperm health, the fallopian tubes, the uterus, embryo development, age and general health.
The science is still developing. Some studies have found potentially meaningful associations, while other research has shown that broad vaginal microbiome categories do not reliably predict IVF outcomes.
This means vaginal microbiome testing should be understood as an additional source of information, not a fertility test, a measure of egg quality or a prediction of implantation.
For someone trying to conceive or preparing for IVF, understanding the vaginal microbiome may help provide a more complete view of reproductive health and support a better-informed conversation with a fertility clinic or specialist.
Knowledge is part of preparation. 

What happens to the vaginal microbiome during menopause?

During perimenopause and menopause, falling oestrogen levels can change the vaginal tissues, acidity and microbiome.
Oestrogen helps support glycogen within vaginal cells. This glycogen helps create conditions in which many Lactobacillus species can thrive.
As oestrogen levels fall, the vaginal microbiome may contain fewer lactobacilli and become more diverse. Vaginal pH may also rise.

These biological changes can be connected with symptoms such as:

• Vaginal dryness or irritation
• Burning or soreness
• Pain during sex
• Urinary urgency or frequency
• Pain when urinating
• Recurrent UTIs
  

These symptoms may form part of genitourinary syndrome of menopause, often shortened to GSM.
A microbiome test cannot diagnose GSM. However, it may provide additional information about how the vaginal and urinary environment has changed. You can then discuss this information with your doctor or a healthcare professional with expertise in menopause.
You do not have to accept vaginal or urinary symptoms as an inevitable part of getting older. Treatments and support are available.

Why should vaginal and urinary health be considered together?

Vaginal and urinary health are closely connected because the vagina, urethra and bladder form part of the same neighbouring biological environment.
Historically, urine was considered sterile. We now know the bladder can contain its own community of microorganisms, known as the urinary microbiome.
The vaginal and urinary microbiomes are not identical, but research suggests that in women they can share some organisms and influence one another. This may be particularly relevant when investigating recurrent urinary symptoms, changes during menopause or symptoms that have not been explained by standard testing.
Sometimes looking at one area alone only gives part of the picture.

What can vaginal microbiome testing tell you?

Vaginal microbiome testing can show which microorganisms were detected in a sample and their abundance relative to one another. Tota also offers full quantification.
Depending on the testing method, it may help show:

• Whether the microbiome is dominated by Lactobacillus
• Which Lactobacillus species are present
• Whether other bacteria are present in higher or lower proportions
• Whether the overall microbial pattern is more mixed
• How the vaginal and urinary microbiomes compare, if both are tested

Traditional tests often look for particular organisms that are already suspected. Tota uses non-targeted DNA sequencing to look broadly across the microbial DNA detected in your sample, rather than checking only a predefined shortlist.
This provides a broader picture of what is there. Your results are then translated into plain English, so you can understand them and discuss them with your healthcare professional.

What can’t a vaginal microbiome test tell you?

A vaginal microbiome test cannot:

• Diagnose every cause of vaginal or urinary symptoms
• Confirm or rule out a UTI
• Replace STI testing, cervical screening or a clinical examination
• Tell you whether you will become pregnant
• Predict the success of IVF or embryo implantation
• Prove that a particular microorganism caused a symptom
• Tell you which treatment is right for you without clinical context
  

Microbiome testing provides information. It should support appropriate healthcare, not replace it.

When might someone consider testing their vaginal microbiome?

You may want to explore vaginal and urinary microbiome testing if:

• You experience recurrent  urinary symptoms
• BV or vaginal symptoms keep returning
• You have an ongoing pattern which hasn’t been explained
• You are preparing for fertility treatment and want additional information
• You have noticed vaginal or urinary changes during menopause
• You simply want to understand your body better
  

Tota is rarely someone’s first step. It is often the point they reach after repeated appointments, tests or treatments have left them without a clear explanation.

When you have tried everything, understanding more may be the next step.

Explore About Our Tests →

Frequently asked questions

Is the vaginal microbiome the same as vaginal flora?

Yes. Vaginal flora is an older term for the microorganisms living in the vagina. Vaginal microbiota refers to the microorganisms themselves, while vaginal microbiome can also include their genes and surrounding biological environment. In everyday use, the terms are often used interchangeably.

Is Lactobacillus always good?

Not necessarily. Many Lactobacillus species help maintain an acidic vaginal environment and are associated with vaginal health. However, different species behave differently, and a healthy vaginal microbiome is not identical in every woman. It’s also possible to experience lactobacillus overgrowth which is too much of it. A microbiome test result needs to be interpreted in context.

Does having lots of different vaginal bacteria mean my microbiome is healthier?

Not necessarily. Unlike the gut, where greater bacterial diversity is often viewed positively, a highly diverse vaginal microbiome can be associated with disruption. However, diversity alone cannot diagnose a health problem.

Can the vaginal microbiome cause a UTI?

The vaginal microbiome may affect susceptibility to UTIs, but it is not the only factor involved. A microbiome test cannot confirm an acute infection or prove why a UTI occurred.

Can the vaginal microbiome affect implantation?

Research has found associations between some vaginal or reproductive tract microbiome patterns and fertility outcomes, but the evidence remains mixed. A vaginal microbiome test cannot predict implantation, pregnancy or IVF success. Read our guide for more detailed information about the link between fertility and the microbiome - [article link].

Does menopause change vaginal bacteria?

It can. Falling oestrogen levels may reduce vaginal glycogen, lower levels of some lactobacilli and increase vaginal pH. These changes may be relevant to vaginal dryness, discomfort, urinary symptoms and recurrent UTIs.

Can I change my vaginal microbiome?

The microbiome can change, but there is no single approach that is right for everyone. Avoid self-treating based on a result alone. A healthcare professional can help you consider your symptoms, medical history and test findings together.

The full picture, finally in your hands

Your vaginal microbiome is not a verdict on your health. It is one part of a much bigger picture.

But when symptoms keep returning, your body is changing or standard tests have not provided an explanation, seeing more may help you ask better questions and have more informed conversations.

Because women deserve better answers.

Explore Vaginal Microbiome Testing →

Frequently asked questions

This article is for general information and is not medical advice. Tota microbiome testing is designed to complement, not replace, clinical testing, diagnosis or treatment.

Sources

1. Ravel J, Gajer P, Abdo Z, Schneider GM, Koenig SSK, McCulle SL, et al. Vaginal microbiome of reproductive-age women. Proc Natl Acad Sci U S A. 2011;108(Suppl 1):4680-4687. PNAS
2. Hugenholtz F, van der Veer C, Terpstra ML, Borgdorff H, van Houdt R, Bruisten SM, et al. Urine and vaginal microbiota compositions of postmenopausal and premenopausal women differ regardless of recurrent urinary tract infection and renal transplant status. Sci Rep. 2022;12. Scientific Reports
3. European Society of Human Reproduction and Embryology (ESHRE). Good practice recommendations on recurrent implantation failure. Hum Reprod Open. 2023;2023(3):hoad023. Human Reproduction Open
4. Graspeuntner S, et al. Vaginal microbial community state types fail to predict IVF treatment outcome. Hum Reprod Open. 2026;2026(2):hoag018. Human Reproduction Open
5. Nieto MR, et al. Menopausal shift on women’s health and microbial niches. npj Women's Health. 2025. Nature
6. NHS. Urinary tract infections (UTIs). NHS
7. NHS. Bacterial vaginosis. NHS

This article is for general information and does not replace medical advice. If you're experiencing new, severe, persistent or worsening symptoms, please speak to a GP or another qualified healthcare professional.